The baloo_file_extractor process in Ubuntu 18.04 LTS takes up a lot of memory. top reports 84.3% of my 15.6 GB, - and some 20% (more or less) of the CPU.
I do not even run KDE, - I am in a Gnome session.
I note that there has previously (in 2014) been a problem with baloo_file_extractor, see How to keep Baloo running but with lower ressource consumption? But I suppose that is fixed. I do not have any external media mounted.
I removed baloo through Synaptic. It turned out to be associated with KDE's file manager, which I had tried but found no advantage over using Ubuntu's. So I removed all of it.
Baloo was using 6 GB of RAM which is ridiculous. I just installed it a week ago, in late August, 2019, I don't think they fixed it! And it had a subprocess that was using a lot of resources as well. Every time I booted up my computer I had to go into process manager and terminal and kill them or my computer would crawl.
I'm not even going to try to fix something like that, that's for KDE/ Kubuntu, if they cared, which they must not. It seems like none of their utilities work properly without creating far more problems than they're worth. I'm running Ubuntu 18.04. I might install the Kubuntu desktop only in time, but I'm leaving its utilities alone!